in the Estonian-language page referred by history1 it is mentioned that Mere did indeed serve in the Ersatzkommando.
This short biography of Mere was, by the way, originally written by Jüri Remmelgas a former war correspondent of the 20. Estn. Kriegsberichter-Zug attached to the Estonian SS-Division. The text is, however, not credited to him on those pages; shame on them.
The additional text at the bottom of the page (Veel huvitavaid fakte) tells that, according to KGB files made public in the 1990´s, Mere had been an NKVD agent in the years 1940-41. His greatest achievement was that he informed the NKVD on an underground group aiming to overthrow the Soviet rule and form a new government. IIRC it has been claimed that Mere was deceiving the NKVD but I cannot remember any details or where I read it.